1. Field of the Invention
The present invention relates to an exposure apparatus and an exposing method, and, in particular, relates to a light exposure performed in a state that an exposing mask having a micro-opening pattern is elastically deformed so as to come in contact with an object to be exposed.
2. Description of the Related Art
Recently, along with progress and diversification in lithographic techniques used for manufacturing semiconductor devices and optical devices, various exposing methods have been proposed as emerging lithographic techniques. Among them, an exposing method is proposed in that micro-fabrication is enabled across the light diffraction limit using nearfield light.
An exposure apparatus employing an exposing method using such nearfield light is proposed in that an exposing mask (membrane mask) made of an elastic body is elastically deformed so as to conform to a resist surface of the object for securely contacting the entire resist surface, and the exposure is made using the nearfield light (evanescent light) passing through the micro-opening pattern.
Such an exposure apparatus (evanescent-light exposure apparatus) using the nearfield light includes means for attaching/detaching the exposing mask to/from an object to be exposed. Such means may include a unit composed of high-pressure gas, a pressure control valve, and a pressurized vessel; and a unit composed of a piston drive motor, a piston, a cylinder, and a pressure control vessel (U.S. Pat. No. 6,171,730, U.S. Pat. No. 6,187,482).
In such a conventional exposure apparatus using the nearfield light, when the exposing mask is caused to contact the object or to detach therefrom, if a rapid compression or decompression is made under certain conditions, an impact load beyond an allowable load of the exposing mask, based on a pressure change applied to the mask, may be applied to the exposing mask.
When such an impact load is applied thereto, in addition to problems that the exposing mask is damaged and the life of the exposing mask is reduced, there are possibilities that the exposing mask naturally oscillates; accuracies in attaching/detaching are reduced due to non-smooth attaching/detaching between the exposing mask and the object; and difficulties in application to various exposing masks.